Roaming not activated as promised!

I activated roaming on MTN- and confirmed it was activated. The call centre agents confirmed all good to go. I have now arrived in Zambia and roaming is NOT working. After several calls made by my husband in South Africa and the agents not willing to assist we eventually found out that I was suppose to receive a code to activate- which was never given! And since I have already left the country there is nothing I can do yo activate! Really??? I will not be returning to South Africa for at least 6 months and need my roaming active to continue with various functions still linked to the number (e.g banking). I have been a contract customer for many years and am appalled that MTN is just once again proving they are NOT keeping up with the times!